Twitter appears to have backtracked on an option that expanded its personal messaging service by allowing users to receive direct messages even from people they were not following.

Thenextweb.comreports that the check box to opt into the new feature, which began appearing last month, is no longer available to users. Twitter’s direct message service, one of its oldest features, typically allows only users who are following each other to exchange messages privately.

Twitter often experiments with new features, offering them to subsets of users and for limited periods, and the company referred inquiries to a company blog post from September that discusses its tendency to test features. In fact, Twitter had opened the featured to some accounts back in 2011.